Sprite is a JavaScript sprite sheet animation library. It uses background-position for animating the sprite sheet and where possible requestAnimationFrame, falling back to setInterval.

Sprite's constructor method.

var foo = new Sprite(...);

• el (DOM Element) - The element that will be animating

var foo = new Sprite(document.getElementById('sprite'));

• frames (Array||Object) - There are multiple ways to define frames, inspired by EaselJS.

Object Using an object is a simple method for inline sprite sheets.

var foo = new Sprite(..., {width: 20, height: 20, length: 4});

• width (Number) - The width of the sprite
• height (Number) - The height of the sprite
• length (Number) - How many sprites there are

Alternatively, allow Sprite to calculate the length by passing the imageWidth and imageHeight as options.

var foo = new Sprite(..., {width: 20, height: 20}, {imageWidth: 40, imageHeight: 40});

• options (Object) - An object to set the default options for this instance.

Along with the standard options these are available

• imageWidth (Number) - The width of the image. Required when length isn't set
• imageHeight (Number) - The height of the image. Required when length isn't set

Array The array definition is useful for more complex sprite sheets with multiple lines and stacked frames. This definition is an Array of Arrays with the following make-up [x, y, width, height]

var frames = [[0, 0, 20, 20], [20, 0, 20, 20], [0, 20, 20, 20], [20, 20, 20, 20]];
var foo = new Sprite(..., frames);

Starts the animation.

• options (Object) - Override any of the options set previously. See Options.

var foo = new Sprite(..., ..., {fps: 12, reverse: true});
// Changed my mind, play at 24 fps and forwards
foo.play({fps: 24, reverse: false, onComplete: fooCompleteHandler});

Stops the animation, optionally on a specific frame.

• options (Object)
  • frame (Number) - Frame number to stop on
  • animated (Boolean) - If stopping should be animated
  • onComplete (Function) - Called on completion of stop

Getter/Setter for frame.

• value (Number) - Which frame to go to

Returns true if the Sprite is animating

Options can be set when instantiating Sprite or overridden when using the play method. Defaults can be changed using Sprite.defaults.

• fps (Number) - Frames per second. Default: 12.
• loop (Boolean||Number) - Boolean or a Number for how many times to loop. Default: true.
• reverse (Boolean) - If the animation plays in reverse. Default: false.
• from (Number) - Frame number to start from and, if loop is false|number the frame it'll stop on.
• onFrame (Function(currentFrame, numLoops)) - Callback on each frame.
• onComplete (Function) - Callback once the animation is complete.

Sprite includes requestAnimationFrame polyfill globally.

Tested in the following browsers

• IE 7 - 10
• Chrome
• Firefox
• Safari
• Opera